IN THE BIGGEST environmental lawsuit ever, the government filed $124 million in complaints last week against Hooker Chemical and its parent company, Occidental Petroleum. Hooker is the perpetrator of the Love Canal disaster, in which leaking chemical dump sites forced hundreds of families to abandon their homes after suffering a variety of chemical-induced illnesses. Love Canal is only one of the hundreds of inadequate dump sites scattered around the country, but it beautifully illustrates the ironies of this insidious form of corporate irresponsibility.

The government's suit covers emergency and permanent cleanup costs for the Love Canal area. If granted, the judgment would also pay for complete health reports on those who lived in the area, and medical follow-up for the rest of their lives. On top of all this, about 1,000 claims for personal and property damage -- totaling more than $2 billion -- have been filed against the city of Niagara Falls, the state of New York and various other parties. A reasonable guess of the final costs would be several hundred million dollars: all of which could have been avoided by the expenditure of $1.4 million in 1950 (about $4 million in today's dollars) to safely dispose of the chemicals in the first place. In other words, it will cost at least 100 times as much to repair the damage as not to have made it.

Ultimately, the costs may prove even greater because the sites are still dangerous even though the companies stopped using some of them more than 25 years ago. The chemicals continue to leach into the ground water and evaporate into the air. Though it hasn't happened yet, the government contends that "at any moment" chemicals could contaminate the drinking water supply, causing a "human health disaster."

Both these characteristics -- the damage that can persist long after a dangerous practice is halted, and the higher costs of cleanup versus proper disposal -- are typical of what happens when hazardous substances are recklessly handled. The worst part of all this is that the damage often can't be remedied, no matter what the cost.

In the light of such experiences, it doesn't much become the chemical industry to continue to complain about the costs of government regulation, and to lobby against tight standards for "cradle-to-grave" management of hazardous substances. In fact, even the most self-interested analysis should indicate that in the long run, it will cost a good deal less to do it right the first time. If that isn't already obvious it should become so soon: the Department of Justice promises that the Hooker lawsuit will be followed by 50 others in 1980.